Electrolyte-as-Cathode Glow Discharge Emission and the Processes of Solution-to-Plasma Transport of Neutral and Charged Species

Emission from an atmospheric-pressure glow discharge with alkali metal chloride solutions used as the cathode was studied. The relation between the discharge emission and the cathode sputtering process leading to the transfer of solution components to the plasma zone was analyzed. It was assumed that the appearance of neutral alkali metal atoms and halogens in the plasma zone is due to the dissociation of halide molecules from a covalently bound state, since the transition to this state becomes possible as a result of excitation of sputtered molecules to high vibrational levels.     

Indolylalkylamines from arylhydrazines and γ- or δ-halocarbonyl compounds (review)

A series of papers devoted to the synthesis of tryptamines and related structures (tryptophols, homotryptamines, eserines, azatryptamines, etc.) from halocarbonyl compounds and arylhydrazines are correlated. The data on the mechanism of the reaction can be successfully applied to the Fischer indole synthesis.     

ISolement du groupe des terres rares de l'apatite par l'acide di-(2-ethyhexyl)phosphorique (hdehp)

The liquid-liquid extraction of rare-earth elements (REE) by 0.75 M di-(2-ethylhexyl) phosphoric acid (HDEHP) in cyclohexane from perchloric acid (1–12M) has been investigated. At moderate perchloric acid molarities (1–6 M), the distribution coefficient, E, has an inverse third-power dependency upon the acid concentration in the aqueous phase. However, at higher perchloric acid concentrations, the slope of the resulting curve is about +18, which means a change in the extraction mechanism. In 12 M perchloric acid medium, REE are quantitatively and selectively extracted from apatite minerals, in the organic phase. In order to strip out all the lanthanides, back-extractions were carried out with 9 M hydrochloric acid solutions.     

Benzindoles

A large amount of structural similarity between 4,5-benzindole and naphthalene and between 6,7-benzindole and indole was detected on a basis of a comparison of the absorption, fluorescence, and phosphorescence spectra of isomeric benzindoles with the spectra of indole and naphthalene. A great analogy between indole and 6,7-benzindole as compared with 4,5-benzindole is also observed during the formation of hydrogen bonds, as indicated by the shift in the absorption band of the NH group in the IR spectra of the investigated compounds in the presence of various proton acceptors.     

Transformations of stereoisomeric 2-chloro-3-R-pentane-1,5-diones in reaction with phenylhydrazine

Monophenylhydrazones were prepared from three monochloro derivatives of arylaliphatic 1,5-diketones, and some their transformations were investigated. The monophenylhydrazones formed regiospecifically, and the direction of the reaction was governed by the substituent attached to C³ atom in the initial chlorodiketones. Formerly unknown products of transformations suffered by monophenylhydrazones obtained were described: 2-amino-1,3-diphenyl-3-(2-phenylindolyl-3)-propan-1-one, 3-benzoyl-2,4,6-triphenyl-2,3,4,5-tetrahydropyridazine, and 3-methyl-1,5-diphenyl-5-phenylazopent-4-en-1-one.     

Steroid polyols from the Far-Eastern starfish Henricia sanguinolenta

A new polyhydroxylated steroid (20R,24S)-5-cholestane-3,6,15,24-tetraol and a known glycoside, laeviuscoloside G, was isolated from the Far-Eastern starfish Henricia sanguinolenta, collected in the sea of Okhotsk, and characterized.     

The temperature dependences of saturated vapor pressures and heat capacities of some perfluoropolyethers

The borling temperatures of perfluoro-2,4,6,9,11,13-hexaoxy-n-tetradecane, perfluoro-2,4,6,8,11,13,15,17-octaoxy-n-octadecane, and perfluoro-2,4,6,8,11,13,15,17,19,21-decaoxy-n-docosane were determined by comparative ebulliometry over the saturated vapor pressure range 6.2–101.6 kPa. The heat capacity of perfluoro-2,4,6,8,11,13,15,17-octaoxy-n-octadecane was studied by adiabatic calorimetry over the temperature range 5.3–371.2 K. The densities of the substances at 296–338 K were measured in quartz pycnometers. The data obtained were used to calculate the normal boiling points, enthalpies of vaporization, critical parameters, and thermodynamic functions (entropy, enthalpy, and Gibbs energy) of the polyethers studied.     

Acid–Base Interactions in the Dichloroacetic Acid–N,N-Dimethylformamide System as Found from IR Spectroscopic Data

Ion–molecule interactions in the dichloroacetic acid–N,N-dimethylformamide system in the concentration range from pure acid to pure base at 30°C were investigated by multiple attenuated total internal reflectance IR spectroscopy. It was found that, depending on the ratio between components in solution, 1 : 1 or 2 : 1 acid–base complexes with strong hydrogen bonds are formed. With an excess of the acid, protonation of the base does not occur. The intensity of continuous absorption at 2000 cm^–1 is characteristic of quasi-ionic pairs with strong symmetrical hydrogen bonds. However, along with a continuous component, the spectra exhibited individual sharp peaks, which are typical of molecular complexes.     

Synthesis and Catalytic Properties of Di- and Trinuclear Palladium Complexes with PCP-Pincer Ligands

Linear and branched conjugated pincer ligands having Ph₂P groups were synthesized: 3,3',5,5'- tetrakis(diphenylphosphinomethyl)diphenylacetylene, 3,3',5,5'-tetrakis(diphenylphosphinomethyl)diphenyldi- acetylene, 1,3,5-tris[3,5-bis(diphenylphosphinomethyl)phenylethynyl]benzene, and hexakis[3,5-bis(diphenylphosphinomethyl)phenylethynyl]benzene. Palladation of these ligands by heating with Pd(BF₄)₂(MeCN)₄ in boiling acetonitrile gave the corresponding di- and trinuclear ionic pincer palladium complexes. No individual complex was obtained from hexakis[3,5-bis(diphenylphosphinomethyl)phenylethynyl]benzene. The ionic com- plexes were converted into the corresponding chloride complexes by treatment with sodium chloride in a mixture of water with methylene chloride. The structure of the ionic palladium complex with 3,3',5,5'-tetrakis(diphenylphosphinomethyl)diphenylacetylene was established by X-ray analysis. The obtained palladium complexes exhibited a considerable catalytic activity in the Heck reaction of iodobenzene with ethyl acrylate and in the Michael addition of ethyl cyanoacetate with methyl vinyl ketone. The catalytic activity per palladium atom decreases as the number of palladium atoms in the complex increases.     

Mathematical modeling of butadiene rubber synthesis process on neodymium-containing catalyst system

The synthesis of butadiene rubber mediated by a lanthanide catalyst system based on neodymium(III) chloride in a batch reactor was mathematically modeled. The mechanism of the process was identified and the rate constants of various reaction steps were determined. It was found that chain transfer reactions with different rate constants have an effect on the molecular-mass characteristics of butadiene rubber.